The invention concerns a method for regenerating a particle filter during the operation of an internal combustion engine, a control unit for an internal combustion engine, an internal combustion engine, and a motor vehicle.
With internal combustion engines, the exhaust aftertreatment systems of which comprise a particle filter, there is frequently the problem that said filters can become blocked in the event of high idling proportions or light load proportions of the internal combustion engine operation, because in said operating regions the exhaust gas of the internal combustion engine is too cold to burn the soot collected in the particle filter and thus to regenerate said particle filter. Typically therefore, at least one loading parameter is recorded that is characteristic of a current loading of the particle filter, wherein depending on the loading parameter an active regeneration measure is carried out recurrently. In this case the term “active regeneration measure” refers to a temperature, in particular the exhaust gas temperature, being actively raised to a value at which the accumulated soot in the particle filter is burnt and said particle filter is thereby regenerated. This takes place actively in the respect that the regeneration does not just take place owing to a raised exhaust gas temperature that would occur anyway because of a suitable operating state of the internal combustion engine, but that the temperature is raised regardless of the operating state of the internal combustion engine using other suitable measures. The regeneration is carried out recurrently in the respect that the loading of the particle filter increases again following completed regeneration, so that finally the particle filter has to be regenerated again. Accordingly, the at least one loading parameter also fluctuates with the current loading of the particle filter.
It is a disadvantage of said procedure that each possible active regeneration measure increases the fuel consumption of the internal combustion engine in addition to the normal operation. In addition, an active regeneration measure is superfluous if an operating state of the internal combustion engine exists or is actually to be expected in the near future, in which the exhaust gas temperature is sufficient to regenerate the particle filter even without an active regeneration measure.